This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
To operate, a control system receives power from a power source. If the control system is within a vehicle, then the power source may include batteries, a motor, a generator, or other similar devices that provide power. By way of example, when the motor of the vehicle is operating, an alternator may supply power to a vehicle's electrical system and may recharge the vehicle's battery. However, when the vehicle is not operating, the battery provides the primary source of power for the vehicle. Some of the control systems may utilize power from either a battery or a motor, while other control systems may operate from both.
Within the vehicle, the control systems may have different modes of operation depending on the source of power. When the vehicle's motor is operating, which may be referred to as a normal mode of operation, the motor may supply power to the various components of the vehicle. While the motor is operating, the power consumption by the various systems may not be a concern because the motor may be able to supply adequate amounts of power. However, when the vehicle is utilizing the battery to supply power to the systems within the vehicle, which may be referred to as a standby mode of operation, the amount of power available to the various systems may be limited. As such, the use of the control systems may vary depending on the mode of operation.
For instance, during the normal mode of operation, the vehicle's electrical system may supply power to a tire pressure monitoring system within the vehicle. Yet, during the standby mode of operation, the tire pressure system may not operate because the use of the vehicle may not need this system when the vehicle is not operating. Alternatively, body electronics, such as remote keyless entry, window control, trunk access, or other similar features, may be utilized during the standby and normal modes of operation. As such, the control systems, such as the body electronics, may function continuously from the operator's perspective.
During the standby mode of operation, the conservation of power may be an issue for the vehicle's control systems. To conserve power, control systems may operate in a substantially continuous mode to conserve power. The substantially continuous operation may appear to operate continuously to a user, but merely operate for brief intervals to periodically monitor for a change in state. This brief operation allows the control system to perform a specific monitoring activity for a first time period. Then, the control system may remain inactive for a second time period to conserve power. As a specific example, a remote keyless entry system may operate once during a 50 millisecond time period to determine whether a signal has been received from a key associated with the vehicle. If no signal is detected, then the remote keyless entry system may be disabled for a second time interval to conserve power for the vehicle. As such, the remote keyless entry system may appear to be continuously operating from the operator's perspective.
However, for a variety of reasons, control systems may be exposed to various environments while in the standby mode of operation, which may effect the operation of the control systems. The various environments may include extreme temperatures, such as freezing or intense heat, for example. The circuits within the control systems may behave in a different manner depending on the environmental conditions. As a result, some of the circuits may not operate as intended because of the environmental conditions.
Accordingly, control systems may utilize circuits with different tolerance ranges to operation as intended. However, the cheaper circuits may not be able to perform within the specific tolerance range. As such, some control systems may utilize more complex circuits to control the operation of the circuits in different environments. These complex circuits may utilize higher priced components that increase the cost of the control system.